/*
 * Copyright (C) 2010, Funcom AS, All Rights Reserved
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  @authors
 *  Svein Gunnar Larsen <sveingunnarlarsen@gmail.com>
 *  Erik Thune Lund <culex.eriklund@gmail.com>
 *  Michel Krohn-Dale <kronicz@gmail.com>
 */

package com.funcom.peeler.action;

import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

public class MultiChange implements Change {

    private List< Change > changes = new LinkedList< Change >();

    public MultiChange( Collection<Change> changes ) {
        if ( changes == null ) throw new NullPointerException( "MultiChange must be created with a valid changelist" );
        this.changes.addAll( changes );
    }

    public void startChange() {
        for ( Change change : changes ) {
            change.startChange();
        }
    }

    public void endChange() {
        for ( Change change : changes ) {
            change.endChange();
        }
    }

    public void doChange() {
        for ( Change change : changes ) {
            change.doChange();
        }
    }

    public void undoChange() {

        ListIterator<Change> iter = changes.listIterator( changes.size() );
        while ( iter.hasPrevious() ) {
            iter.previous().undoChange();
        }
    }

    public boolean valid() {

        for ( Change change : changes ) {
            if ( !change.valid() ) return false;
        }

        return true;
    }
}
